• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.185-196
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• 2006

Newcastle disease (ND) is a highly contagious disease of poultry that can cause severe economic losses throughout the world. Vaccination has been used for a long time and proved as one of the most effective method to reduce the economic loss due to ND virus infection, The measurement of antibody titer such as hamagglutination-inhibition (Hl) test with sera has been used as a useful method to evaluate the immunity leve of host. However, Hl test is gradually being replaced by the enzyme linked-immunosorbent assay (ELISA), To evaluate the efficacy of ELISA in the chickens vaccinated with different procedure, present study has been performed. After SPF chicks and commercial broilers were vaccinated with different kinds of live vaccines such as V4, VG/GA and/or Bl at various time, the antibody level has been measured using both HI test and ELISA. Challenge test with velogenic viscerotropic NDV was also performed to measure the protective level of antibody. In the SPF chickens, the mean ELISA titer after vaccination and survival rate after challenge was increased and correlated with days post inoculation. More than 80% of chickens with higher than 1,000 ELISA titer after vaccination were survived after challenge with velogenic ND virus and had good correlation between survival rate and antibody titier. In commercial broiler chickens, most of them at market age had low level of ELISA titer regardless of the number of vaccination, and had a low correlation between survival rate and ELISA titer. However, the ELISA titer of remaining birds after challenge was increased. This result indicated that ELISA titer had good response against velogenic NOV infection compared to Hl titer.

• Korean Journal of Veterinary Service
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• v.24 no.2
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• pp.147-159
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• 2001

This Study was conducted to determine vaccination programs for the control of Newcastle Disease(ND) in chickens and investigate protective effect against Newcastle disease virus (NDV) after live ND vaccination. Maternal HI antibody titer level of chickens according to day(age) 1, 7, 14, 21, 28 and 35 were decreased gradually as 7.10$\pm$0.74, 6.57$\pm$0.74, 3.71$\pm$1.25, 2.20$\pm$1.03, 1.20$\pm$1.23 and 0.50$\pm$0.71. As a result of HI test and ELISA, both chickens vaccinated with VG/GA strain live vaccine at 1-day-old and chickens not vaccinated do not have antibody titer for protection against NDV at 14-day-old. Except for LaSota strain vaccine, in case of vaccination with VG/GA spray and VG/GA, B1 and LaSota strain drinking water at 14-day-old, the protective effect was 100% in chickens inoculated NDV($10^{7.2}$ $EID_{50}$/50${\mu}\ell$, eye drop) at 21-day-old, but not 10～50% at 28-day-old. These data suggest that live NDV vaccination should be given at 10-day-old 20-25day-old for protect against NDV at periodic outbreaks of ND caused by velogenic viscerotropic NDV in the environment of a farm.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.46-55
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• 1998

This study was performed to verify the effect of modified live virus vaccine against canine parvovirus (CPV) infection. Serum hemagglutination inhibition (Hl) test, histopathological and immunohistochemical techniques and polymerase chain reaction were used. The results were as follows: 1. During the experimental terms after vaccination, serum Hl titer was stable. Geometric mean titer (GMT) after the 1st vaccination was 280. After virulent CPV was challenged, GMT was 1,306. 2. After challenge by virulent CPV, the vaccinated group was not shown clinical signs and gross and histopathological findings. 3. After challenge by virulent CPV, the vaccinated group was not detected viral antigens in the small intestine immunohistochemically. 4. After challenge by violent CPV, the vaccinated group was not shown virus shedding in feces. In conclusions the overall results confirmed that modified live virus vaccine was effective on prevention of canine parvovirus infection.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.223-229
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• 2006

Recently canine parvovirus(CPV) enteritis had been controlled successfully by the use of low-passage high titer modified live CPV vaccines. However, outbreaks of CPV enteritis have been continued in Korea. In this study, we carried out epidemiological investigation on the recent outbreaks of CPV enteritis of dogs and determined the potential prognostic factors affecting the survival of dogs. The total of 140 dogs diagnosed for CPV enteritis were statistically analysed. The majority of dogs were from 6 to 18 weeks of age and were not vaccinated or incompletely vaccinated. There were significant difference in the survival rate between male and female dogs with CPV enteritis and among the age groups(p<0.05). Moreover, there was significant difference in the survival rate of dogs between HI titer <80 group and HI titer 160 group(p<0.05). The majority of dogs had a history of diarrhea, vomiting, lethargy and dehydration. It was considered that recent outbreak of CPV enteritis in Korea caused by the failure of vaccination and/or by the inadequate antibody responses to CPV vaccines. Prophylactic measures should include isolation of young dogs from the dog population until the vaccination can be expected to provide protection.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.1024-1028
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• 2003

Influenza-associated encephalopathy is regarded as one of the major neurologic disease entities along with those of Reye syndrome, acute necrotizing encephalopathy, and myelitis which are known to be related to influenza virus, mostly type A. And it is being actively researched in Japan as it has caused a tremendous increase in the number of deaths from 1997 to 2002, but it has not been yet reported in the Korean pediatric medical community. It attacks those previously healthy children, who have not been vaccinated. Patients start with such symptoms as fever and common respiratory problems, but within 24 to 48 hours they suffer from seizures with acute mental deterioration, become worse, and suffer multiple organ failures including marked elevated transaminase levels as well as coagulopathy. It induces deaths in a couple of days after the symptoms appear or remains a serious neurologic sequelae. Confirmative diagnosis is used to demonstrate influenza viral infection. We report here a 37 month aged boy who was admitted to our hospital during the last influenza season under the diagnosis of influenza associated encephalopathy on the basis of serologic testing by hemagglutinin inhibition(HI). This is the first report confirmed by increased antibody titer of the influenza A virus in Korea.

• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.213-221
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• 2010

The results from a total of 412 blood samples consisted of 187 samples from regular visiting group (RV), 94 samples from first visiting group (FV), 52 samples from abandoned group (A), 54 samples from special breeder group (SB), and 25 samples from preliminary breeder group (PB) showed that RV(94.7%) and SB(88.9%) groups had the higher levels of protective antibody, but PB (36.0%) group revealed the lowest level. Among 96 blood samples with lower protective antibody levels, 14 samples (14.6%), 72 samples (75.0%) and 10 samples (10.4%) were below the protective antibody levels to distemper/parvo-virus, distemper only and parvovirus only, respectively. These results implied that antibody to parvovirus was well generated than that to distemper. Eighty six samples (20.9%) showed the protective antibody titer under 1:96 to distemper and 24 samples (5.8%), the protective antibody titer under 1:40 to parvovirus.

• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.225-232
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• 1990

The immune responses of commercial layer chickens against Newcastle disease (ND) were compared among different administration methods and times of vaccination during 4 weeks of age. A total of 372 day-old chickens were devided into 4 groups of 93 birds each. Each of 3 groups was received a commercially available B$_1$ live vaccine via drinking water, eye instillation or spray method at one, 14 and 28 days of age. One group was used as an unvaccinated control. At two and 4 weeks after each time of vaccination, 15 birds from each group were challenged with virulent ND virus at the dose of 10$^{5}$ EID$_{50}$ per bird to examine the pretection rate. Ten to 15 birds from each group were bled at two weeks intervals from day old to 8 weeks of age to determine hemagglutination inhibition antibody titer. The protection rate was generally low regardless of the times of vaccination although two or more times vaccination gave higher protection than once vaccination. The low protection was considered due to low titer of the vaccine used since the vaccine titer was less than 10$^{2.5}$ EID$_{50}$ per bird. Spray method gave better protection compared to eye instillation of drinking water method which resulted in lowest response. When birds were challenged majority showed clinical signs on ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression (96%), drowsy(90%), anorexia (84%), diarrhoea (29%), difficult breath (15%) and torticollis (10%). Hemorrhagic lesions on post mortem were seen in duodenum (51%), trachea(36%), illeum (13%), ceacal tonsil (11%), proventriculus (10%) and some other organs. When birds were challenged majority showed clinical signs on ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression (96%), drowsy(90%), anorexia (84%), diarrhoea (29%), difficult breath (15%) and torticollis (10%). Hemorrhagic lesions on post mortem were seen in duodenum (51%), trachea(35%), illeum (13%), ceacal tonsil (11%), proventriculus (10%) and some other organs.

• Journal of Food Hygiene and Safety
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• v.5 no.3
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• pp.111-120
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• 1990

Effects of royal jelly(RJ) on the immune system in normal and cyclophosphamide(CY)-treated mice were investigated. The results were as following: 1. Body weight, spleen weight, thymus weight, WBC, cell-mediated immunity (CMI, contact hypersensitivity to DNFB), humoral immunity (HI, Hemagglutinin-, Hemolysin-titer) were increased or decreased dependent on the day of administration of RJ in normal mice. But it showed no effect on liver weight and RBC. 2. Combined treatment with RJ in CY-treated mice on the day which RJ showed the increasing activities in normal mice inhibited the decrease of survival rate, body weight, spleen weight, WBC and CMI caused by CY, but no effect on the decrease of thymus weight and HI induced by CY.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.308-313
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• 2006

This study was performed to monitor the level of serum canine parvovirus(CPV) antibody titers in adult dogs throughout the Korea from January 2003 to April 2004. A total of clinically healthy 885 dogs between 1 year and 17 years old were included in this study. Serum antibody titers against CPV were measured by means of hemagglutination inhibition(HI) titers at the time dogs were brought to the hospital for revaccination. Most of dogs had been primarily vaccinated or previously revaccinated. Dogs were grouped by age, breed, sex, and primary vaccination and revaccination to determine whether these factors were associated with antibody titers. Serum CPV titers ${\geq}80$ were considered protective. Protective antibodies against CPV were present in 95.0% of the population. Breed, age, and primary vaccination and revaccination were not significantly associated with serum CPV antibody titers. But sex was significantly associated with CPV antibody titers. The results of this study have shown that there is a need to reconsider the annual revaccination strategy against CPV infection.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1960-1965
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• 2015

Rabbit hemorrhagic disease virus (RHDV) is highly contagious and often causes fatal disease that affects both wild and domestic rabbits of the species Oryctolagus cuniculus. A highly pathogenic RHDV variant (RHDVa) has been circulation in the Korean rabbit population since 2007 and has a devastating effect on the rabbit industry in Korea. A highly pathogenic RHDVa was isolated from naturally infected rabbits, and the gene encoding the VP60 protein was cloned into a baculovirus transfer vector and expressed in insect cells. The hemagglutination titer of the Sf-9 cell lysate infected with recombinant VP60 baculovirus was 131,072 units/50 μl and of the supernatant 4,096 units/50 μl. Guinea pigs immunized twice intramuscularly with a trial inactivated RHDVa vaccine containing recombinant VP60 contained 2,152 hemagglutination inhibition (HI) geometric mean titers. The 8-week-old white rabbits inoculated with one vaccine dose were challenged with a lethal RHDVa 21 days later and showed 100% survival rates. The recombinant VP60 protein expressed in a baculovirus system induced high HI titers in guinea pigs and rendered complete protection, which led to the development of a novel inactivated RHDVa vaccine.